Ofsted is to launch a crackdown on "boring" teaching in response to concerns that children's behaviour is deteriorating because they are not being stimulated enough in class.

Inspectors will be told to give more finely tuned advice to struggling schools on what is going wrong in their lessons and why pupils are not paying attention, the chief inspector of schools, Christine Gilbert, said.

She told the Guardian the changes in the inspections would amount to a "crackdown" on boring teaching. "I think that it should do that. When I was a [local authority] director of education I wanted to know if there was a link between boredom and achievement. We did a piece of work on it and there was strong evidence that a lot of it was boredom."

Teaching unions said the chief inspector was unfairly portraying the profession.

The inspectorate's latest annual report, published in November, warned of "pedestrian" teaching in primary schools, and said pupils in secondary schools were too often set tasks that are not demanding enough of them. "The result is their loss of interest, their slow progress and, often, deteriorating behaviour," it said. Some teachers fail to inspire pupils by relying on textbooks and endlessly preparing for tests, the document warns.

Gilbert said: "People divorce teaching from behaviour. I think they are really, really linked and I think students behave much better if the teaching is good, they are engaged in what they are doing and it's appropriate to them. Then they've not got lost five minutes into the lessons and therefore started mucking around. Behaviour in our schools is generally very good. But there's what I would describe as low-level disruption where children are bored and not motivated, so they start to use their abilities for other ends. That then can lead to other children being distracted in lessons and so on."

She said that a focus on improving schools through the introduction of better and stronger management and head teachers "isn't enough" to make every lesson good - schools should be improving the quality of teaching too. She said reforms to the inspection process would make a difference.

"One of the things that we've been concerned to do in the new inspection framework is to really emphasise the importance of teaching and learning. One of the things we really felt it was important to do is to give much clearer information about what schools should do.

"I read every special measures report every week. Every single one. Too often they say you've got to improve teaching and learning and literacy and numeracy. The school isn't left with enough information. There's been a dialogue in the school but often, particularly in special measures, they don't take it in at the time. I think we need to be much clearer in our recommendations of what schools need to do in terms of their teaching and learning."

The consultation on the new Ofsted inspection regime suggested that inspectors would spend more time in classrooms observing the quality of lessons.

Teachers' leaders reacted angrily to the comments. Chris Keates, the general secretary of the NASUWT teaching union, said: "The fact is that every chief inspector seems to get infected with a virus that makes them say schools are full of teachers who aren't good enough despite the fact that their own evidence shows the standards of teacher is good. With comments like that, the chief inspector fuels the view that every lesson of every day for every minute has got to be packed with excitement. Quite frankly life isn't like that and education isn't like that. Comments like this make teachers fair game for everyone, including pupils."

Margaret Morrissey, a former school inspector and founder of the parental campaigning group Parents Outloud, said: "There's always been the odd teacher who some children will find boring, but in life what turns off one child will turn on another. We'll never live in a utopia where every teacher fascinates every child."

John Bangs, the head of education at the National Union of Teachers, said: "The quality of teaching over the last 10-15 years is the best it's ever been. I wish she would present her findings in a way that reflects reality. It would be helpful if inspectors gave schools more information on how to improve - they need a two-way conversation about what's going on when they are put into special measures." A strong focus on teaching and learning in inspections would be welcomed, Bangs added.